Method and apparatus for making sand cores



Jan. 14, 1930. F. H. MOREHEAD 1,743,231

METHOD AND APPARATUS FOR MAKING SAND CORES Filed Feb. 8, 1928 2 Sheets-Sheet l Jan. 14, 1930. MOREHEAD 1,743,281

METHOD AND APPARATUS FOR MAKING SAND CORES Fil d F 1928 2 Sheets-Sheet INVEN'L V:

Patented Jan. 14, 1930 Unites States FRENCH H. MOREHEAD, OF BOSTON, MASSACHUSETTS METHOD AND APPARATUS FOR MAKING SAND CORES Application filed February 8, 1928. Serial No. 252,770.

fect as for instance by subjecting the core after it is in place in the mold to stresses which tend to bend the core in the direction opposite to that produced by its tendency to float. The tendency of the core to float and thus be distorted can also be overcome by employing a core which is bent the right amount during its manufacture so that when the metal is poured the tendency to float brings it to the desired straight position. present invention, therefore, has for its object a method and apparatus for making suitable bent cores rapidly and economically.

It is the object of the invention to produce by rotation cores adapted to overcome the above mentioned dificulties and which may be straight but not of circular cross section or to produce bent cores which may or may not be of circular cross section, any of which may be uniform or variable in cross section from end to end. In the practice of my invention, suitable core sand is deposited on a rotating arbor and is trimmed by a suitable knife as it rotates, either the arbor, or the knife or both being moved and preferably flexed in time with the rotation of the arbor. In practice I prefer to bend the knife, but I do not limit myself tothis specific form, and intend to claim my invention broadly since as already stated the same or equivalent results can be obtained by bending the arbor orgiving the. knife and arbor proper rela- I same,and

tive movements.

The apparatus embodying my invention is simple and effective and will produce suitable cores as fast as apparatus which produces straight cores, and the cores so produced can be employedin ordinary molds without employing any means to bend them after they are placed in the mold or to hold them against bending due to their tendency to float in the molten metal; therefore, casting with cores made in accordance with the process embodying my invention is much simplified and cheapened. Tubular articles produced by the use of the cores so made have a uniform cross-section and therefore metal is saved. The number of defective articles which must be rejected is reduced and the articles have a longer life, all with no additional expense in manufacture.

Before explaining in detail the present invention, and the method or mode of opera tion embodied therein, it is to be understood that the invention is not limited in its application tothe details of construction and arrangement of parts illustrated in the accompanying drawings since the invention is capable of other embodiments and of being practiced or carried out in various ways. Also it is to be understood that'the phraseology or terminology employed herein is for the purpose of description and not of limitation, and it is not intended to limit the invention beyond the terms of the several claims hereto appended or the requirements of the prior art.

The invention will be more clearly understood from the following description in conjunction'with the accompanying drawings; in which Fig. 1 is an elevational view partlyiin section of'one type of apparatus for producing the specially shaped c'ore Fig. 2 is a plan view taken upon 22 of Fig. 1;

Fig. 3 is a similar view of the apparatus with a different type of arbor; V

'Fig. 4 is an end elevational view, partly broken away, of another type of apparatus for producing the core;

- Fig. 5 is a side elevational view of the the line Fig. .6 is a sectional view taken upon the line 66 of Fig. 5. g V

Referring to the drawings, the apparatus comprisesfFigs. 1, 2 and 3) a support 10 car-- m0 rying a suitable frame 11 in which an arbor 14 is rotatably mounted. The arbor 14 may be in the form of a hollow pipe provided near each end with grooves 15 forming bearing surfaces for rolls l6 fixed upon shafts 17 suitably mounted for rotation in bearings 18 in the frame 11.

The arbor 14 may be rotated by mecha nism at each end thereof including a shaft 20 rotatably mounted in suitably bearings 21.

in the frame and provided at one end with a spline or key 23 adapted .to'engage a keyway 24 in the ends of the arbor. The shafts 20 may be rotated in synch ronism and for this purpose each is provided with a gear 25 operatively connected with "a gear 22"on a shaft 9 rotatably mounted in the frame. A

pulley or sprocket'wheel 8 is secured upon one 7 of the shafts 20 and may be driven from any suitable source of power to rotate the shafts 20 and arbor in synchr'onismf The frame 11 is proyided with suitable lugs 26 extending toward the arbor 14 and upon which a knife 27 capable of being flexed is mounted. The knife '27 is provided with extending support as by screws 39,

eccentric or cam 40 is secured upon. one end of a shaft 41 rotatably mountedin suitable bearings 42 inthe'frame, and is arrangedfor operative engagement with the stirrup 33. The 7 Cam v4O may be actuated in any suitablemanner in timed relation with the rotation of the arbor, and for this purpose, a driving gear 44 is, mounted'on theishaft and is" operativcly connected with a gear 45 securedon the shaft 41 byan idler gear 46 secureduponv shaft'47 rotatably mounted i th if amzljf.

Th ar r ybe fa iyg ui a lr har depending upon the type. anu-p shapg of core which is to be produced. The typesf of arbors illustrated are adapted for. rise. the production of cores employed "fonmjaking pipes; This arbor majy" "be of cylin drical form, as shown igL 3, or it may provi ded with an abnormal bend, asjshovvn in Fig. 2,"substantially. equal; to lithe bend de-.

" i e be pro uqs ie lle i d or any case the arbor "shouldbeprqyided with tabl pen n si qreunit eapeqt e e formed by contact of the mgltenjrg t l hesand core.

- "e ui al eh upe 59 t a pears. any

nv n e t ma t a by a t ine abov thearbor 14 and is provided at its lower end with a chute 52 extending to a point close to the arbor. A riddle 53 is suspended within the hopper and is provided with upwardly extending arms 54 pivotally mounted upon shafts 56 secured in the frame 57 extending upwardly from the hopper.

' In the manufacture of cores, power is supplied to rotate the arbor 14 and flex the knife 27 in timed relation. The desired fiexure of theknife may be produced by selecting a suitably shaped cam or eccentric 40. A suitable mixture of sand and binder is introduced into the riddle 53and the latter is vibrated, whereupon the sand and binder mixture passes downwardlythrough thehopper 5(land chute 52 and is deposited upon the arbor 14 with considerable impact. '7 The sand will clingfto the surface of the arbor due, to the presence of the binder admixed therewith and will.

build uponthe arbor until asufiicient amount has accumulated to engage the effective edge of the shaping knife '27. i The knife will shear off any excess of sand and binder mixture and shape the same. to the form of the.

core desired. Thev supply of sand, and binder is then cut off and the arbor isrotated through one or two revolutions thereafter. V

In Figs. 4, 5 and. 6 Ihay'e shown a type ,of

apparatus for making a crooked core by fiexlng 'or'bending the. arbor during its rotation. As illustrated; in this form of apparatus the knife is held stationary with its edge straight.

This apparatus comprises.:asuitablesupport 60 having". a frame'61 extending upwardly near each end of the apparatusfor .rotatably supporting. rolls 62. upon which the 'no rmally straight arbor 63 rests cross m ember 64 in which a roll'65 is rotatably mounted is pivoted at oneend tothe frametll detach; ably securedthereto, as by a boltfifijand nut 7, at its e he n the arrangement b i g such} fast to bring the. roll 65 intofjelig g ement w th, he. r and hold. the same: aga ns t 291 s Baum: i mta t eit The m re s it b ee v f g ave, as a ac en ms l to?" 'h e esie t With the 5 1. 8 62 mafia:

" An. uter r me 70 extends upwa dly f om a "snpp' t twin i speedrema h. fia'm' .61 and is provi ed. a i s e}? th a c'f aY lae-r'estiiln72ff rr in "t of'a-journalfo i n qcent 1? a as 'suit bl A- cross member is pivotally mounted at one su a at Qr e fam mm. is .de-

t ee-, by a t' s rev. 7

ta h bly ecuredto h iothe Si e as y liifi'75 a bbltve. A Shaping knif 3 secured;'as byjscrews 7 8, to 79 Qnne n ames 61-. M hearbQrmaY be ptafiedhy me h nism a eat d i sl ii e' ha tfill r v ded t on qltefs's'f m m arbor. The other end of the shaft 80 is connected by a universal joint 88 to a shaft 84 rotatably mounted in the frame. The driving mechanism at each end of the arbor may be connected to operate in synchronism. For this purpose each shaft 84 may be provided with a gear 85 operatively connected with a gear 86 near each end of a shaft 87 rotatably mounted in the frame. This mechanism may be operated from any suitable source of power transmitted for example to a pulley 88 mounted upon the shaft 84.

In operation of the apparatus shown in Figs. 4, 5 and 6 a suitable mixture of sand and binder is deposited upon the rotating arbor through a chute 90 from a hopper of the general type previously described. During rotation the eccentrics 7 3 will cause flexure or bending of the arbor 63 and the sand mixture 91 accumulated upon the arbor will be shaped by the knife 77 to cylindrical form. The amount of flexure of the arbor will be controlled by the character of the eccentrics 73. When the flexed arbor having the cylindrical body of sand mixture thereon is removed from the apparatus it will tend to straighten and thereby impart a curvature to the accumulated sand mixture 91 to provide a crooked core.

I claim:

1. The method ofmaking a core which comprises depositing a suitable sand mixture on a revolving arbor, and shaping the sand mixture thereon bycontact with a knife, said knife and said arbor being moved relatively towards and away from one another during the rotation of the arbor in such a way as to vary the distance between the arbor and the knife diflerent amounts at different points longitudinally of the arbor.

2. The method of making a core which comprises depositing a suitable sand mixture on a revolving arbor, shaping the mixture by a knife during the rotation of the arbor, and flexing one of said members relative to the other during the rotation of the arbor.

3. The method of making a core which comprises depositing a suitable sand mixture upon a revolving arbor, shaping said mixture by a knife during rotation of said arbor, and moving said knife towards and away from said arbor during the rotation of the arbor in such a way as to vary the distance between the arbor and the knife different amounts at different points longitudinally of the arbor.

4. The method of making a core which comprises depositing a suitable sand mixture upon a revolving arbor, shaping said mixture by a knife during rotation of said arbor, and flexing said knife relative to said arbor in timed relation with the rotation of the arbor.

5. In an apparatus for making sand cores, a rotatable arbor, means for depositing a suitable sand mixture upon the arbor, a knife for shaping said mixture, and a cam operating in timed relation with the rotation of the arbor and acting upon said knife to flex it in timed relation with the rotation of the arbor.

6. In an apparatus for makinv sand cores, a rotatable arbor, means for depositing a suitable sand mixture upon said arbor, a knife 

